The mechanical testing of thin layers of soft materials is an important but difficult task. Spherical indentation provides a convenient method to ascertain material properties whilst minimising damage to the material by allowing testing to take place in situ. However, measurement of the viscoelastic properties of these soft materials is hindered by the absence of a convenient yet accurate model...

There are two competing descriptions of nematic liquid crystal dynamics: the Ericksen-Leslie director theory and the Eringen micropolar approach. Up to this day, these two descriptions have remained distinct in spite of several attempts to show that the micropolar theory includes the director theory. In this paper we show that this is the case by using symmetry reduction techniques and introduc...

Abstract The effective thermal expansion coefficient β∗ of a binary viscoelastic composite is shown to be frequency dependent even if the thermal expansion coefficients βA and βB of both constituents are themselves frequency independent. Exact calculations for binary viscoelastic systems show that β∗ is related to constituent values βA, βB , volume fractions, and bulk moduli KA, KB , as well as...

The present study deals with the analysis of unsteady boundary layer flow and heat transfer of an incompressible micropolar fluid over a stretching sheet when the sheet is stretched in its own plane. The velocity and temperature are assumed to vary linearly with the distance along the sheet. Two equal and opposite forces are impulsively applied along the x-axis so that the sheet is stretched, k...

In this paper free convection from a horizontal isothermal elliptic tube placed in a micropolar fluid with its major axis vertical is investigated. The governing equations are based on the conservation of mass, linear momentum, angular momentum and energy. The full governing equations written in stream function-vorticity formulation are solved numerically using the Spectral method based on Four...

The paper deals with the investigations of boundary layer stagnation point flow and heat transfer characteristics of an electrically conducting micropolar fluid impinging normally on a permeable horizontal surface in the presence of a uniform magnetic field. The fluid is considered to be non-Newtonian, whose flow is governed by the equations of a micropolar fluid. The governing continuity, mome...

the preparation and characterization of the vinyltriethoxysilane-modified silica nanoparticles were investigated. also the surface tension of polystyrene, native (hydrophilic) silica and silane-modified (hydrophobic) silica were determined. two kinds of polystyrene/silica (treated and non-treated) nanocomposites were prepared with different filler loadings by solution method. their viscoelastic...

The viscoelastic behavior of binderless carbon black compacts under dynamic compression (0.2–10.0 Hz, static strain 1.0–2.5%, deformation amplitude 9.4–16 lm and packing density 0.18–0.45 g/cm) is governed by the solid part of the compact, with the elastic character dominating the viscous character. The viscous character increases with increasing aggregate size, while the elastic character decr...